js-canvas图片验证码
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2022-02-08 10:31:38
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效果图如下:
第一种:html+js canvas图片验证码
代码如下:
<!DOCTYPE html>
<html>
<!-- head -->
<head>
<title>图片登录验证</title>
</head>
<body>
<input type="text" value="" placeholder="请输入验证码(区分大小写)" style="height:43px;position: relative; top:-15px; font-size:20px;" id="text">
<canvas id="canvas" width="100" height="43" onclick="dj()" style="border: 1px solid #ccc;
border-radius: 5px;"></canvas>
<button class="btn" onclick="sublim()">提交</button>
</body>
<script>
var show_num = [];
draw(show_num);
function dj() {
draw(show_num);
}
function sublim() {
var val = document.getElementById("text").value;
var num = show_num.join("");
if (val == '') {
alert('请输入验证码!');
} else if (val == num) {
alert('提交成功!');
document.getElementById(".input-val").val('');
draw(show_num);
} else {
alert('验证码错误!\n你输入的是: ' + val + "\n正确的是: " + num + '\n请重新输入!');
document.getElementById("text").value = '';
draw(show_num);
}
}
function draw(show_num) {
var canvas_width = document.getElementById('canvas').clientWidth;
var canvas_height = document.getElementById('canvas').clientHeight;
var canvas = document.getElementById("canvas"); //获取到canvas的对象,演员
var context = canvas.getContext("2d"); //获取到canvas画图的环境,演员表演的舞台
canvas.width = canvas_width;
canvas.height = canvas_height;
var sCode = "A,B,C,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,W,X,Y,Z,1,2,3,4,5,6,7,8,9,0,q,w,e,r,t,y,u,i,o,p,a,s,d,f,g,h,j,k,l,z,x,c,v,b,n,m";
var aCode = sCode.split(",");
var aLength = aCode.length; //获取到数组的长度
for (var i = 0; i <= 3; i++) {
var j = Math.floor(Math.random() * aLength); //获取到随机的索引值
var deg = Math.random() * 30 * Math.PI / 180; //产生0~30之间的随机弧度
var txt = aCode[j]; //得到随机的一个内容
show_num[i] = txt;
var x = 10 + i * 20; //文字在canvas上的x坐标
var y = 20 + Math.random() * 8; //文字在canvas上的y坐标
context.font = "bold 23px 微软雅黑";
context.translate(x, y);
context.rotate(deg);
context.fillStyle = randomColor();
context.fillText(txt, 0, 0);
context.rotate(-deg);
context.translate(-x, -y);
}
for (var i = 0; i <= 5; i++) { //验证码上显示线条
context.strokeStyle = randomColor();
context.beginPath();
context.moveTo(Math.random() * canvas_width, Math.random() * canvas_height);
context.lineTo(Math.random() * canvas_width, Math.random() * canvas_height);
context.stroke();
}
for (var i = 0; i <= 30; i++) { //验证码上显示小点
context.strokeStyle = randomColor();
context.beginPath();
var x = Math.random() * canvas_width;
var y = Math.random() * canvas_height;
context.moveTo(x, y);
context.lineTo(x + 1, y + 1);
context.stroke();
}
}
function randomColor() { //得到随机的颜色值
var r = Math.floor(Math.random() * 256);
var g = Math.floor(Math.random() * 256);
var b = Math.floor(Math.random() * 256);
return "rgb(" + r + "," + g + "," + b + ")";
}
</script>
</html>
第二种:vue中实现 canvas图片验证码
代码如下:
<template>
<div class="check-text">
<div class="check-v">
<el-input class="check-input" placeholder="请输入验证码" v-model="checkValue"></el-input>
<canvas id="canvas" @click="dj"></canvas>
</div>
<div class="check-b">
<el-button type="primary" class="btn" @click="sublim">提交</el-button>
</div>
</div>
</template>
<script>
export default {
name: "check-text",
data() {
return {
checkValue: "",
show_num: []
};
},
mounted() {
this.draw(this.show_num);
},
methods: {
//得到随机的颜色值
randomColor() {
var r = Math.floor(Math.random() * 256);
var g = Math.floor(Math.random() * 256);
var b = Math.floor(Math.random() * 256);
return "rgb(" + r + "," + g + "," + b + ")";
},
// 加载验证码canvas
draw(show_num) {
var canvas_width = document.getElementById("canvas").clientWidth;
var canvas_height = document.getElementById("canvas").clientHeight;
var canvas = document.getElementById("canvas"); //获取到canvas的对象,演员
var context = canvas.getContext("2d"); //获取到canvas画图的环境,演员表演的舞台
canvas.width = canvas_width;
canvas.height = canvas_height;
var sCode =
"A,B,C,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,W,X,Y,Z,1,2,3,4,5,6,7,8,9,0,q,w,e,r,t,y,u,i,o,p,a,s,d,f,g,h,j,k,l,z,x,c,v,b,n,m";
var aCode = sCode.split(",");
var aLength = aCode.length; //获取到数组的长度
for (var i = 0; i <= 3; i++) {
var j = Math.floor(Math.random() * aLength); //获取到随机的索引值
var deg = (Math.random() * 30 * Math.PI) / 180; //产生0~30之间的随机弧度
var txt = aCode[j]; //得到随机的一个内容
show_num[i] = txt;
var x = 10 + i * 20; //文字在canvas上的x坐标
var y = 20 + Math.random() * 8; //文字在canvas上的y坐标
context.font = "bold 23px 微软雅黑";
context.translate(x, y);
context.rotate(deg);
context.fillStyle = this.randomColor();
context.fillText(txt, 0, 0);
context.rotate(-deg);
context.translate(-x, -y);
}
for (var i = 0; i <= 5; i++) {
//验证码上显示线条
context.strokeStyle = this.randomColor();
context.beginPath();
context.moveTo(
Math.random() * canvas_width,
Math.random() * canvas_height
);
context.lineTo(
Math.random() * canvas_width,
Math.random() * canvas_height
);
context.stroke();
}
for (var i = 0; i <= 30; i++) {
//验证码上显示小点
context.strokeStyle = this.randomColor();
context.beginPath();
var x = Math.random() * canvas_width;
var y = Math.random() * canvas_height;
context.moveTo(x, y);
context.lineTo(x + 1, y + 1);
context.stroke();
}
},
// 点击验证
sublim() {
let $this = this;
let num = $this.show_num.join("");
if ($this.checkValue == "") {
$this.$message({
message: "请输入验证码!",
type:'error'
});
} else if ($this.checkValue == num) {
$this.$message({
message: "提交成功!",
type:'success'
});
$this.$this.checkValue = ''
$this.draw($this.show_num);
} else {
$this.$message({
message: '验证码错误,请输入正确的验证码!',
type:'error'
});
$this.checkValue = ''
$this.draw($this.show_num);
}
},
// 点击验证码刷新
dj() {
this.draw(this.show_num);
}
},
watch: {}
};
</script>
<style lang='scss' scoped>
.check-text {
width: 300px;
height: 100px;
border: 1px solid #333;
.check-v {
width: 300px;
height: 40px;
.check-input {
width: 180px;
height: 40px;
float: left;
}
#canvas {
width: 100px;
height: 40px;
float: right;
border:1px solid #333;
}
}
.check-b {
width: 300px;
height: 60px;
padding-top: 20px;
.btn {
width: 300px;
}
}
}
</style>
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